Imidazolines having polyalkenylsuccinimido-containing substituents



United States Patent 3,415,750 IMIDAZOLINES HAVING POLYALKENYLSUCCIN- IMIDO-CONTAINING SUBSTITUENTS Joseph F. Anzenberger, St. Louis, Mo., assignor to Monsanto Company, St. Louis, Mo., a corporation of Delaware No Drawing. Continuation-impart of application Ser. No. 313,768, Oct. 4, 1963. This application May 19, 1967, Ser. No. 639,610

12 Claims. (Cl. 252-515) ABSTRACT OF THE DISCLOSURE Compounds of the class which are polyalkenylsuccinimido imidazolines and polyalkenylsuccinimido bis-imidazolines which can be utilized as ashless detergents in lubricating oil compositions.

This application is a continuation-in-part of application Ser. No. 313,768, filed Oct. 4, 1963, now abandoned.

This invention relates to certain new imidazolines and bis-imidazolines useful as detergents in lubricating com positions.

Under the conditions encountered in a large percentage of present-day automobile driving (i.e., the so-called stopand-go driving), automobile engines do not attain their most desirable and efiicient operating temperatures. As a result, large quantities of oil-insoluble products are formed which eventually find their way into the crankcase by flowing past the piston rings. Since most of these products are oil insoluble, they tend to deposit on the internal parts of the engine, resulting in further inelficient engine operation. In present-day practice, deposition of the oxidation products is minimized by incorporating into lubrieating oils detergents which keep the oxidation products dispersed. Generally, the detergents in use today are metalcontaining compounds. The use of metal-containing detergents, however, has not been totally satisfactory since such detergents form ash deposits in the combustion chambers of engines, fouling the spark plugs and creating other problems such as preignition.

It has now been found that the problems associated with the use of metal-containing detergents can be avoided by the use of certain new imidazolines which are nonmetallic or ashless detergents or dispersants. The new imidazolines which are the subject of the present invention are also useful as inhibitors of rust in internal combustion engines and the like and in gasoline fuel compositions;

The new mono-imidazolines of this invention can be where R is a polyalkenyl radical having a molecular weight of from about 700 to about 2500, preferably about 900 to about 1500; R and R are selected from the group consisting of hydrogen and a methyl radical; R is selected from hydrogen, an alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, alkenyl, substituted alkenyl, aryl, substituted aryl or heterocyclic radical and a substituted heterocyclic radical and can contain from one to twenty carbon atoms; x is a Whole number from 0 to 3; and Z is selected from alkylene and alkenylene. For convenience, imidazoline, as used herein, is intended to include both the monoand bis-imidazolines.

The imidazolines of this invention can be prepared by reacting (a) a polyethylene polyamine (referred to herein as a polyamine), represented by the structure with (b) a carboxylic acid, that is,

(i) a monocarboxylic acid represented :by the structure i R-d-OH or the anhydride thereof, or

(ii) a dicarboxylic acid represented by the structure or the anhydride thereof, to produce an intermediate of the structure which intermediate is in turn reacted with (c) a polyalkenylsuccinic anhydride represented by the structure or the acid thereof, where R, R R R x and Z have their aforedescribed significance. The mole ratios of (a) :(b):(c) will be about 1:1:1, respectively, to prepare mono-imidazolines and about 2:2:1, respectively, to prepare bis-imidazolines. However, where the acid anhydride is used in place of the carboxylic acid the mole ratio of (a):(b):(c) will be about 111:0.5, respectively, in the case of mono-imidazolines and 2:2:1.0, respectively, 1n the case of the bis-imidazolines.

The imidazolines and bis-imidazolines can in the alternative be prepared by first interacting the polyalkenylsuccinic anhydride, that is, (c) and (a) to produce a polyalkenylsuccinimide. This intermediate can then in turn be interacted with a carboxylic acid represented by (b) to form the monoor bis-imidazoline. It is preferred, however, to interact (a) with (b) to produce the monoor bisimidazoline amine followed by interaction with the polyalkenylsuccinic acid (c). In the preparation of the monoand bis-imidazolines of this invention, the carboxylic acid represented by (b) liberates about two moles of water for each mole of carboxylic acid that is interacted with one mole of the ethylenepolyamine. In the case of starting with a dicarboxylic acid to produce the bis-imidazolines of this invention, four moles of water are eliminated when two moles of an ethylenepolyamine are interacted with one mole of a dicarboxylic acid.

In carrying out the process of this invention, it is preferred to prepare the monoand bis imidazoline amine intermediates. In general, temperatures in the order of about 125 C. to about 250 C. are utilized in preparing the monoand bis-imidazoline amine intermediates, preferably from about 150 C. to about 225 C. In order to facilitate the removal of water, solvents can be utilized, such as xylene, toluene or a mineral oil. In addition, in order to facilitate the removal of water a reduced pressure can be utilized to complete cyclization to the imidazoline. The preferred method to prepare the monoand bis-imidazoline amine intermediates is to utilize 2. reduce pressure until the elimination of the theoretical amount of water is obtained. In addition, a two-step process can be utilized, that is, refluxing a solvent such as toluene or xylene to remove water, followed by removal of the toluene or xylene under reduced pressure which reduced pressure technique removes the additional water necessary to cyclize to the imidazoline ring. The reduced pressure can be maintained for a period of from 1 to 12 hours, preferably at least 2 hours. In general, at temperatures of about 150 C. to about 250 C. reaction times in the order of about 2 to 6 hours are sufiicient under reduced pressure. At atmospheric pressure and at preferred temperatures of from about 175 C. to 225 0., times in the order of 3 to 15 hours are sufficient to obtain dehydration to the imidazoline ring.

The monoand bis-imidazoline amine intermediates are in turn reacted with the polyalkenylsuccinic anhydride or acid represented by (c). In general, temperatures in the range of from 100 C. to 250 C. are suflicient to complete the formation of the monoand bis-imidazoline compounds of this invention at times of from 1 to 24 hours, preferably from 2 to 8 hours. As in the preparation of the monoand bis-imidazoline amine intermediates, a solvent can be utilized to remove the water that is formed during imide formation. In addition, a reduced pressure can be utilized at the temperatures and for the times as stated above for the preparation of the amine intermediates.

The polyalkenylsuccinic anhydrides useful in preparing the imidazolines of this invention can be prepared from an olefin or olefin polymer and maleic anhydride. Preferably a polymer of a lower olefin, or copolymer of lower olefins is used, for example, polymers of ethylene, propylene, butylene, isobutylene and copolymers or mixtures thereof, having a molecular weight of from about 500 to about 2500, but preferably about 800 to about 1500. The preparation of the polyalkenylsuccinic anhydrides is best effected at temperatures of the order of about to 250 C. by reacting maleic anhydride with the olefin polymer in mole ratios of from 1:1 to about 5:1, respectively. Since the reaction between the olefin and maleic anhydride may not go to completion, the resulting polyalkenylsuccinic anhydride can contain some unreacted olefin which can be allowed to remain as a diluent with no harmful effects upon the performance of the compounds of this invention.

Typical non-limiting examples of the polyamines which can be used in preparing the compounds of this invention are diethylenetriamine, di(methylethylene)triamine, triethylenetetramine, tri(methylethylene)tetramine, tri(et'hylethylene)tetramine, tetraethylenepentamine and pentaethylenehexamine.

In the case of the monocarboxylic acids useful in preparing the mono-imidazolines of this invention, the following are representative.

(a) Aliphtic monocarboxylic acids (i) Where R is an alkyl or substituted alkyl radical.- Formic acid, acetic acid, fluoroacetic acid, propionic acid, beta-chloropropionic acid, butyric acid, isobutyric acid, nitroisobutyric acid, valeric acid, isovaleric acid, hexanoic acid, heptanoic acid, 2-ethylhexanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, undecanoic acid, tetradecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, eicosanoic acid, docosanic acid and triacontanoic acid.

(ii) Where R is an alkenyl or substituted alkenyl radical.-Butenic acid, pentenic acid, hexenic acid, teracrylic acid, hypogeic acid, oleic acid, elaidic acid, linoleic acid, alpha-eleostearic acid, beta-eleostearic acid, alphalinolenic acid, acrylic acid, beta-chloroacrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, 3-butenoic acid, angelic acid, senecioic acid, hydrosorbic acid, sorbic acid and 4-tetradecenoic acid.

(b) Alicyclic monocarboxylic acids Cyclopropanecarboxylic acid, cyclopentanecarboxylic acid, cyclohexanoic acid, hydrocapric acid, chaulmoogric acid, naphthenic acid, 2,3,4,5-tetrahydrobenzoic acid and cyclodecanecarboxylic acid.

(0) Aromatic monocarboxylic acids Benzoic acid, l-naphthoic acid, Z-naphthoic acid, 0- toluic acid, m-toluic acid, p-toluic acid, o-chlorobenzoic acid, rn-chlorobenzoic acid, p-chlorobenzoic acid, 2,3-dibromobenzoic acid, 3,4-dichlorobenzoic acid, o-nitrobenzoic acid, rn-nitrobenzoic acid, p-nitrobenzoic acid, 2, 3-dinitrobenzoic acid, salicylic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, gallic acid, anisic acid, phenylacetic acid and beta-phenylpropionic acid.

(d) Heterocyclic monocarboxylic acids Picolinic acid, nicotinic acid, furylacrylic acid, piperic ac1d, indoxylic acid, 3-indoleacetic acid, cinchoninic acid, furoic acid, 2-thiophenecarboxylic acid, 2-pyrrolecarboxylic acid, 9-acridancarboxylic acid, quinaldic acid, pyrazionic acid and antipyric acid.

In the case of the dicarboxylic acids useful in preparing the bis-imidazolines of this invention, the following are representative:

(a) Aliphatic dicarboxylic acids (i) Where Z is an alkylene radical.Oxa1ic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pi-melic acid, suberic acid, azelaic acid, sebacic acid, brassylic acid and thapsic acid.

(ii) Where Z is an alkenylene radical.lMaleic acid, furnaric acid, glutaconic acid, citraconic acid, itaconic acid, ethidenemalonic acid, mesaconic acid, allylmalonic acid, allylsuccinic acid, teraconic acid, xeronic acid and cetylmalonic acid.

It is also contemplated herein to employ dimeric and trimeric polycarboxylic acids to produce the hisimidazolines of the present invention. When two like or unlike molecules of a polyethenoic monocarboxylic fatty acid condense to form a dicarboxylic acid, the product by definition is a dimer acid, or the carboxylic acid is said to be dimerized. In general, the dimer acids suitable for use in this invention are produced by the condensation of two like or unlike unsaturated aliphatic monocarb'oxylic acids having between about 16 and about 18 carbon atoms per molecule, examples of which comprise A -hexadecacadienoic acid A -heptadecadienoic acid A -octadecadienoic acid A -octadecadienoic acid A -octadecadienoic acid (linoleic acid) A -octadecadienoic acid A -octadecatrienoic acid A -octadecatrienoic acid (linolenic acid) The preparation of specific imidazolines of this invention is illustrated in the following non-limiting examples, wherein parts are parts by weight unless otherwise stated. 1

Example 1 To a 300 ml. glass reactor equipped with stirrer, addition funnel, Dean-Stark trap, reflux condenser and heating means is added 37.9 grams (0.2 mole) of tetraethylenepantamine and 30 m1. of toluene. To this solution is added acetic acid, 12 grams (0.2 mole), dropwise at a rate so as not to exceed 40 C. in the reaction flask. After addition is completed, the reaction mixture is heated slowly to 210 C. which temperature is maintained for a period of about 2 hours. After a period of about 2 hours, 7.2 ml. of water is obtained. The temperature is allowed to reach 120 C. and the reaction flask is put under a 20 ml. vacuum for a period of 2 hours. The product, 43.5 grams, is determined to be 1-(3,6,9-triazanonyl)-2-methylimidazo1ine. The amount of water that is produced is the theoretical amount of water for the formation of an imidazoline ring, that is, 7.2 ml. of water. The infrared spectrum shows the presence of C=N-- with no amide present. The ultraviolet absorption spectrum confirms the formation of C=N. Nuclear magnetid resonance determines the presence of the 2 methylene carbon atoms which are part of the imidazoline ring and in addition the presence of a methyl group at the 2-position of the imidazoline ring. The above spectral data confirms the formation of an imidazoline ring with no amide present.

Example 2 To a conventional glass reaction is added 178.7 grams (0.1 mole) of polybutenylsuccinic anhydride in 70 ml. of toluene. The temperature is increased to 90 C. and 21.8 grams (0.1 mole) of 1-(3,6,9-triazanonyl)-2-methy1- imidazoline is added dropwise over a period of 11 minutes. The temperature is increased to 96 C. and 30 ml. of toluene is added to the reactor. The temperature is increased to 128 C. and this temperature is maintained for a period of 3 hours. 1.8 grams of water is obtained after the 3 hour period. The temperature is increased to 150 C. and the toluene removed. Infrared spectrum confirms the imide formation.

Example 3 To a 1-liter, round bottom, 4-necked flask equipped with stirrer, thermometer and heating means is added 23 grams (0.1216 mole) of tetraethylenepentamine, 70 grams of xylene and 10.7 grams (0.1216 mole) of butyric acid. The temperature is increased to 50 C. for

a period of approximately one hour. A 30* mm. of Hg. pressure is then applied and the temperature increased to 210 C., which temperature is maintained for a period of 2 /2 hours. The temperature is reduced to ambient temperature and 4.3 grams of water is collected, 2.2 grams in a dry ice trap during the vacuum step. The product is 1-(3,6,9-triazanonyl)-2-propy1 imidazoline. To the imidazoline compound is then added 35 grams of a light oil together with 217.0 grams (0.1216 mole) of polybutenyl(l300)succinic anhydride. The temperature is increased to C. and a vacuum applied for a period of 2 hours. The product 1-[8-polybutenyl(1300)succinirnido]-3,6-diaZaoctyl-2-p1opy1imidazoline is obtained.

Example 4 Into a suitable reaction vessel, fitted as described above, which contained 90.8 grams of tetraethylenepantamine (0.48 mole) in 200 ml. of toluene is charged 640 grams of polybutenyl(980)succinic anhydride in 50 ml. of toluene. This reaction mixture is heated to reflux and maintained at reflux for about 2 hours with stirring until the evolution and collection of water ceases. The reaction mixture is cooled to about 75 C. and then 167.8 grams of naphthenic acid (0.48 mole) is added. Refluxing continues until the evolution and collection of water from the reaction ceases. A vacuum is applied and the toluene removed. The temperature is increased to C. under a 20 mm. vacuum for a period of 3 hours. The vacuum is reduced to a 1 mm. for a period of 2 hours. The prodnot, 173 grams, is 1-[8-polybutenyl(980)succinimido]- 3,6 diazaoctyl 2-naphthenyl-2-imidazoline, which after analysis has 2.84% nitrogen with a base number of 1.36.

Example 5 In the manner of Example 4, 810 grams of polybutenyl(980)succinic anhydride (0.64 mole) is reacted with 65.9 grams of diethylenetriamine (0.64 mole) in 300 ml. of toulene. After sufiicient reflux with the collection of all the by-product water the reaction mixture is cooled and 181 grams of oleic acid (0.64 mole) is slowly added. Refluxing is continued until the evolution and collection of water ceases. A vacuum is applied to remove the toluene and the temperature is increased to 155 C. for a period of 2 hours. The temperature is then allowed to reach 100 C. and an 0.5 mm. of Hg vacuum was applied for a period of 4 hours. The product, 1,013 grams is 1-[2-(po1ybutenyl( 980) succinimido)-ethyl]-2 heptadecenyI-Z-imidazoline which analyzes 2.21% nitrogen with a base number of 0.68.

Example 6 In the manner of Example 4, 1600 grams of polybutenyl(980) succinic anhydride is reacted with 175 grams of triethylenetetramine in 150 ml. of toluene. The reaction mixture is heated to reflux and refluxed until the evolution and collection of water of the reaction ceases. Upon cooling 59.2 grams of acetic acid are slowly added and then reflux is continued until further evolution and collection of water ceases. A vacuum is applied and the toluene removed. The temperature during toluene removal is 150 C. maintained for a period of 4 hours. The temperature is lowered to 110 C. and an 0.5 mm. vacuum applied for a period of 2 /2 hours. The product, 1751 grams, is 2- methyl 1-[polybutenyl(980)succinimido]-3-azapentyl-2- imidazoline which analyzes 1.55% nitrogen.

Additional examples of other imidazolines of his invention prepared utilizing the procedures of Examples 4, 5 and 6 and the materials used for their preparation are given in Table I below. In the table only the alkenyl, or polyalkenyl, portion of the polyalkenylsuccinic anhydride and the average molecular weight of such portion are given, DETA means diethylenetriamine and TEPA means tetraethylenepentamine.

TABLE I Alkenyl portion of Example alkenylsuccinic Poly- Ne. anhydride ethylene Carboxylic acid Molar ratio Product (mole wt. of Polyamine alkenyl group) 8 Polybuteuyl (1368).... DETA Picolinio acid..." 1:1:1 l-[2-(po1ybutenyl(1368)suceinimido)-ethyl]-1- v alpha-pyridylimidazoline. 9 do TEPA Benzole acid 1:1:1 1-[8-(polybutenyl(1368)succinimido)-3,6-

I 4 diazaoctyl]-2-phenylirnidazoline 10 P01ybutenyl(980) TEPA Adlpic acid 2:2:1 2,2tetramethylene bis[l-(8-polybntenyl(980)- 4 succinimido-3,S-diazaoctyl)-2-imidazoline]. l1 .do TEPA Sebacic acid 212:1 2,2-octamethylene bis[1-(8-polybutenyl(980)- succinimido-3,G-diazaoctyD-Z-imidazoline]. 12 Polybutenyl (1368).-.. TEPA Dimer acid (con- 2:2:1 2,2-dilinoleie bis[l-(8-polybutenyl(1368)succint girlnng 336 imido-S,6-diazaoctyl)-2-imidazoline].

r ons In a similar manner the other imidazolines contemplated by this invention can be prepared.

The imidazolines of this invention can be used in lubricating oils in amounts of from about 0.01% to about 25% by weight. Additive concentrates of 60-95% are also conte-mplated. It has been found, however, that in finished formulations, for most applications, amounts of from about 0.25% to about 10% by weight are sufiicient. In addition, the compounds of this invention can be used in fuel oils and in various light products, such as gasoline, wherein they also function as detergents or dispersants.

A screening test was utilized to demonstrate the detergency effectiveness in lubricating oil formulations of the imidazolines of this invention. This test, referred to as a Lacquer Deposition Test, involves passing partially oxidized gasoline through a sample of an oil formulation in a suitable container under controlled conditions, after which the sample is aged in an oven. The amount of deposit is then determined by washing away the oil. A control formulation is run simultaneously. The figure reported represents the percent reduction in deposits when a detergent is present as compared to the amount of deposit when no detergent is present. The great advantage of the Lacquer Deposition test is that the results obtained correlate well with the results which are obtained in low temperature gasoline engine tests such as the Lincoln MS Test.

TABLE II Test No. Concentration, Imidazollne LDT result,

wt. percent percent reduction 1 Example 2 100 2 Example 4 83 2 Example 5 91 2 E\ample 6 97 From the above, it is clear that the addition to lubricating oils of the imidazolines of the present invention brings with it a clear improvement of the dispersing and/ or detergent qualities of said oils. As is clearly apparent from the results of Table II, the imidazoline compounds of this invention exhibit outstanding detergent properties. In particular, Table II clearly demonstrates that the presence of an imidazoline ring provides detergent properties regardless of the method that is used to prepare the particular imidazoline compound. Thus, Test No. 1 has an LDT test result of 100%. In particular, the mono-imidazoline of Example 2 (Test No. l) was prepared by first interacting the monocarboxylic acid with the polyethylenepolyamine to form the intermediate imidazoline compound. The imidazoline amine compound was then interacted with the polybutenylsuccinic anhydride to produce an imidazoline compound of this invention. The result obtained utilizing the procedure of Example 2 clearly shows that the detergent qualities of imidazoline compounds are not affected by the method of its preparation.

Since the greater part of the commercial lubricating oils sold today are subject to a large number of uses, it is, therefore, generally necessary to employ more than one type of additive in a finished lubricant composition. Thus, although the products of the present invention are efitectivev detergents-dispersants, it is frequently necessary to use such products in combination with other types of additives, such as metal-containing detergents and/ or dispersants, corrosion inhibitors, oxidation inhibitors, extreme pressure agents, viscosity index improvers, pour-point depressors, antifoaming agents and the like.

A particularly useful combination of additives intended to be applied in motor lubricants is the combination of an additive of the present invention and a metal-containing derivative of phosphorus such as metal phosphorodithioate, e.g., zinc dihexyl phosphorodithioate, the zinc salt of mixed alkyl phosphorodithioates where the alkyl groups are obtained, for example, from an equal mixture of isobutyl and n-amyl alcohols, and the metal salts of phosphorus sulfide-olefin polymer reaction products and combinations thereof.

Lubricating oils which can be used as the base oils to which the new compounds of this invention are added are not limited as far as detergent effects are concerned, and accordingly, can be lubricating oils which are of a naphthenic base, paraifinic base, and other hydrocarbon bases, as well as lubricating oils derived from coal products and synthetic oils, such as alkylene polymers, alkylene oxide polymers, dicarboxylic acid esters, alkylated benzenes, silicate esters, silicon polymers and the like, are suitable.

While this invention has been described with reference to various specific examples and embodiments, it is understood that the invention is not limited thereto and that it can be variously practiced within the scope of the following claims.

The embodiments of the invention in which an exlusive property or privilege is claimed are defined as follows:

1. A bis-imidazoline compound represented by the formula where R is a polyalkenyl radical having a molecular weight of from about 700 to about 2500; R and R are selected from the group consisting of hydrogen and a methyl radical; x is a whole number from 0 to 3 and Z is selected from the group consisting of alkylene, alkenylene and a single valence bond.

2. A compound of claim 1 wherein Z contains from 0 to 18 carbon atoms.

3. A compound of claim 2 wherein Z is selected from the group consisting of alkylene and a single valence bond.

4. A compound of claim 3 wherein R and R are hydrogen.

5. A compound of claim 4 wherein R has a molecular weight of from about 900 to about 1500.

6. A compound of claim 3 wherein x has a value of from 1 to 3.

7. A compound of claim 5 wherein x has a value of from 1 to 3.

8. A compound of claim 7 wherein Z is alkylene having from 1 to 10 carbon atoms.

9. A composition comprising a major amount of a lubricating oil and from 0.01% to about 25% by weight of a compound of claim 1.

10. A composition comprising a major amount of a lubricating oil and from 0. 01% to about 25% by weight of a compound of claim 2.

11. A composition comprising a major amount of a lubricating oil and from 0.01% to about 25% by weight of a compound of claim 5.

12. A composition comprising a major amount of a lubricating oil and from 0.01% to about 25% by weight of a compound of claim 8.

References Cited UNITED STATES PATENTS White et al. 25251.5 Osuch 252--51.5 Le Suer 252-515 Norman et al 25251.5 Bell et al. 25251.5 Le Suer et a1 252-515 Anzenberger et al. 25251.5 Vineyard 25247.5

PATRICK P. GARVIN, Primary Examiner.

US. Cl. X.R.- 

